Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare a safe idempotent read, so the description invests in adding context instead of repeating it: it discloses the identity prerequisite and, crucially, that absence of a record is not evidence of failure. It does not cover result shape or freshness/staleness of the lookup.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, no filler, and the core behavior (lookup by key) leads before the cautionary retry rule. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description correctly spends its words on return semantics — that a miss is not a failure — plus the auth prerequisite, which is what an agent needs to interpret and safely retry. Complete for a two-parameter lookup.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the burden, and it does name both parameters inline and label 'operation' as optional. However it adds no semantics for the key's format, the meaning of 'operation' values, or the 128/200 length bounds, so it only partially compensates for the coverage gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('look up an own write') and the mechanism that identifies it ('by its idempotency key and optional operation'). Clear enough to act on, but it never contrasts itself with plausible siblings like get_job_status or get_submission_status, which the name alone doesn't disambiguate.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives real operational guidance: missing records do not prove failure, retry only with the same key and payload, and a connected identity is required. It stops short of naming an alternative tool or stating upfront when reconciliation is appropriate versus a direct status check.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.